| Chlorinated organic compounds are used widely in chemical engineering, and also bring about much serious pollution. At present, chlorinated organic compounds are mostly treated on basis of reducing pollution, not thinking about reusing. In this paper, the gas phase catalytic hydrogenation technology is brought out to reduce the pollution of chlorinated organic compounds,1,2-dichlorothane is used as the typical chlorinated organic compound.The main products of1,2-dichloethane are ethane and ethylene, the propose of the experiment is to choose a suitable catalyst and its modification method to improve the selectivity of ethylene because ethylene is more important than ethylene in chemical engineering.Pd-Cu/γ-Al2O3catalysts of two synthetic methods with varied metal loadings were prepared by the co-impregnation method and deposit-reduction method respective. The Pd-Cu/y-A2O3catalysts were all characterized by elements analysis, X-ray powder diffraction, N2adsorption, CO adsorption and Transmission electron microscopy. And then the synthetical catalysts were used for the gas phase catalytic hydrodechlorination of1,2-dichloroehtane in turn. We testes the effects of reaction temperature Pd/Cu ratio and the reaction time on the1,2-dichloroehtane conversion and ethylene selectivity. Results of those catalysts indicate that palladium-copper alloy are formed when increasing Cu loading and ethylene selectivity are enhanced. Furthermore, at250℃, the bimetallic catalyst with0.78%of Pd and1.9%of Cu when the synthetic method is co-impregnation method exhibits optimum catalytic behavior with the ethylene selectivity higher than80%, and at250℃, the bimetallic catalyst with0.91%of Pd and1.96%of Cu when the synthetic method is deposit-reduction method exhibits optimum catalytic behavior with the ethylene selectivity higher than86.7%.In addition, we discussed the catalytic mechanism of1,2-dichloroethane through analyzing the characterization and the results of catalytic reduction of 1,2-dichloroethane. |
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